1. Field
Example embodiments relate to a flow limiter that may reduce a moisture carry over (MCO) level at an exit of a fuel bundle of a nuclear reactor. Example embodiments also relate to a system that includes the flow limiter.
2. Description of Related Art
In conventional boiling water reactors, fuel assemblies including nuclear fuel rods are used to convert water to steam. The steam may be used for various purposes, for example, as a reheating medium or as a force to drive a turbine. In conventional nuclear reactor plants, the fuel assemblies interface with a fuel support casting.
During the operation of a boiling water reactor, water is supplied to a fuel bundle through a fuel support casting. Ideally, the water exits the fuel bundle as pure steam. However, after a certain number of cycles, a fuel bundle will inevitably become a low power bundle and will be moved to one of the outer, peripheral rows along with the other low power bundles. Nevertheless, even if a low power bundle is arranged in one of the outer, peripheral rows, the steam exiting the low power bundle may still contain an increased amount of water droplets if the amount of incoming water exceeds the ability of the low power bundle to convert all of the water to steam.
The amount of water droplets in the steam exiting a fuel bundle may be referred to as a moisture carry over (MCO) level. A high moisture carry over level may be detrimental to the operation of a boiling water reactor for at least two reasons. First, a high moisture carry over level may increase the amount of radiation exposure to plant operators. Second, a high moisture carry over level may cause damage to the blades of the steam turbine. Consequently, nuclear power plants typically opt to reduce core flow in order to decrease moisture carry over levels. However, a reduction in core flow results in a reduction in reactor power which ultimately results in decreased revenues.